I have attached a pic of the exhaust tips on my boat. 38ZX Donzi with HP500EFI stock motors and Bravo I XZ drives. The boat has the Corsa Quick n Quiet Plus system. My question is are the baffles (2nd pic) causing extra backpressure that could be robbing RPMs, could they just be removed or do I need to replace the tips with a different type. I'm not looking for a large expense but would like a bit more noise as well as any "free" power I am missing. thanks for the help.

Steve

pic of baffle

Read this thread

http://offshoreonly.com/forums/showt...threadid=39150

Steve,
I have the very same tips and would like to get the answer to your guestion as well. My concern is does this tip have internal flappers ?

I don't think you will see much increase on a stock engine The 6" corsa are rated to 525 Hp (so they say) I will be in the process of gutting mine next week I will let you know how they turn out. there is no internal flapper but the baffles in combination with the external salsbury flapper will prevent the in rush of water. I ran straight pipes on my PQ last summer without the flappers and had no problems I just gave it a little gas when comming off plane. But it may also depend on your boats depth and angle ect.

I was thinking if I can get a 3 7/8 hole saw in there it might work out slick. It would take out the welds and then I would have just a little grinding.

Ray, please keep me informed on how your project goes next week. I did not think when I posted last night about the external flappers...temp brain dead....anyway will the baffles just slide out after the flat plate is cut out?, or is there more cutting to do? You just became the "offical" ginnie-pig for this project. Incidently, I am doing this more for the sound than a performance gain. The boat is a 02 Baja H2x that runs a 496 ho 72.8 on gps

Thanks and I hope you had a good holiday.
JIM

I removed the inserts from my quick & quiet. It doesn't have flappers internally and adds about 25% more noise but no noticable horsepower gains.

Thanks for the replies. I'll await the outcome of Ray's project before proceeding.

Steve

I looked at them today, It does not look easy, I have concidered a plasma arc cutter, stick welder with large electrode and a die grinder. Also the center bolt is tack welded to the nut. One problem I see is the bafflles once cut will be larger than the 4" outlet, requiring a bend or cut to make them smaller to get them out. I have 6 to do on the tripple engine boat so I need to find the easist way. I may just replace the tips but that could prove a job too.

Removing those Corsa quick and quiet system surely must help the engine breath easier once removed even if there isn't much of a speed gain. Any "wet" exhaust system will hurt performance as well. Any time you can reduce back pressure and thus reduce the contamination of exhaust getting into the new air/fuel charge it will at least give you better fuel economy although you may not see much of a speed increase with the boat. As they say; "results may vary"